Div overlap with opaque background
HTML
<div>
AB
</div>
<div class="overlapping">
CD
</div>
CSS
div {
background-color: lightblue;
width: 100px;
height: 100px;
font-size: 3rem;
display: flex;
align-items: center;
justify-content: center;
}
.overlapping {
position: relative;
top: -50px;
left: 50px;
border: 1px solid white;
}